Final answer:
Azure Blueprints Service is backed up using the built-in versioning and change tracking features, where new immutable versions are created upon publishing. External backup can be achieved by exporting blueprints to version control systems like Git.
Step-by-step explanation:
The question relates to the backup process for the Azure Blueprints Service. Azure Blueprints is a service that helps with setting up governed environments by creating, updating, and deploying repeatable Azure resources with a set of built-in components such as Azure Resource Manager templates, role assignments, policy assignments, and resource groups. To back up Blueprints, you typically rely on the built-in versioning and change tracking features of the service. Every time a blueprint is published, a new version is created. These published versions are immutable, thus acting as a backup that you can redeploy or reference at any time. Moreover, there are tools and scripts available that allow you to export blueprints to source control systems like Git, where they can be version-controlled and backed up externally.